Slashdot videos: Now with more Slashdot!

View

Discuss

Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

Hugh Pickens DOT Com writes "Mathematician Edward Frenkel writes in the NYT that one fanciful possibility that explains why mathematics seems to permeate our universe is that we live in a computer simulation based on the laws of mathematics — not in what we commonly take to be the real world. According to this theory, some highly advanced computer programmer of the future has devised this simulation, and we are unknowingly part of it. Thus when we discover a mathematical truth, we are simply discovering aspects of the code that the programmer used. This may strike you as very unlikely writes Frenkel but physicists have been creating their own computer simulations of the forces of nature for years — on a tiny scale, the size of an atomic nucleus. They use a three-dimensional grid to model a little chunk of the universe; then they run the program to see what happens. 'Oxford philosopher Nick Bostrom has argued that we are more likely to be in such a simulation than not,' writes Frenkel. 'If such simulations are possible in theory, he reasons, then eventually humans will create them — presumably many of them. If this is so, in time there will be many more simulated worlds than nonsimulated ones. Statistically speaking, therefore, we are more likely to be living in a simulated world than the real one.' The question now becomes is there any way to empirically test this hypothesis and the answer surprisingly is yes. In a recent paper, 'Constraints on the Universe as a Numerical Simulation,' the physicists Silas R. Beane, Zohreh Davoudi and Martin J. Savage outline a possible method for detecting that our world is actually a computer simulation (PDF). Savage and his colleagues assume that any future simulators would use some of the same techniques current scientists use to run simulations, with the same constraints. The future simulators, Savage indicated, would map their universe on a mathematical lattice or grid, consisting of points and lines. But computer simulations generate slight but distinctive anomalies — certain kinds of asymmetries and they suggest that a closer look at cosmic rays may reveal similar asymmetries. If so, this would indicate that we might — just might — ourselves be in someone else's computer simulation."

Looping or restarting is one thing, the fact that someone's running us in the background while playing a galactic edition of their favourite strategy game raises a whole other set of existential questions.

Indeed. He doesn't notice that math is a set of abstractions that humans use to model their environment. It would be a pretty awful model if he didn't look out and see those patterns.

It is like a glass maker looking in a mirror and deciding that glass has humans inside. No, really, you should know this stuff.

And if he sees so many patterns, he should probably look at all the warts, too. "Natural" numbers are natural to humans, but those aren't the numbers/proportions nature uses. If math was really modeling the universe well, we would have whole numbers for constants: e, c, k, pi. Math is very useful, and at human scale we mostly don't notice the lack of symmetry. The different things in the universe that we model with math are often symmetrical to each other. But the math is not perfectly symmetrical to the individual components in nature.

First, your exact real-world problem doesn't make sense with a divisor that is less than one, which is how you get close to zero. Five dollars divided into 0.5 parts? What does that even mean?

Now let's flip around your real world example to something that makes sense. Five dollars divided into how many parts, where each part gets $0.50? 5/0.50 = 10 parts. Five dollars divided into how many parts, where each part gets 0.0000001? 50000000. Five dollars divided into how many parts, where each part gets 0? Infinity.

You're partly right in that we can define divide-by-zero how we want, but there are serious problems when it is defined (e.g. as infinity) as it leads to a huge amount of inconsistencies in other areas. The simplest example is the typical proof that 1 = 2 which uses a divide-by-zero to lead to absurdity. If you want consistent numbers, then division by zero needs to be undefined.

Agreed, that was sloppy of me. "Cogito, ergo sum" is however used as a stepping stone for Descartes to "prove" that reality is not an illusion, since sensory perception is not an act of will. Therefore they are external to the thinker, and there exists an external world that provides the thinker with these sensory perceptions.

Personally, if I had my own simulation, there would be a god, and it'd be me. I'm sure it'd run slower because of all the omniscient stuff that would have to go an about intent and action, but it'd be worth it to strike evildoers with lightning every time they got out of line. Anyway, slower or not, no one in the simulation would know, because they'd measure time by their own perceptions and environment, which, of course, would also be running slower.

That happens all the time! You just have to stuff enough mass in one place to overflow the mass counter! Fortunately for the simulation, the localized error-handling keeps the whole damn thing from crashing.

If A * B = C and C / B = A, you can't have B being zero without C being also zero (in which case the equation is valid for all values of A, a.k.a undefined). For every other value of C the equation has no solution. The only reason IEEE defined division by zero as infinity was to make errors easier to handle [ieee.org].

The behavior of light in the 2 slit experiment might be an example of this.

I find it hilarious, though, that people are open to this possibility but so hostile to the idea of creationism. Both amount to the same sort of situation: a created universe, rather than one devoid of any design or purpose.

I find it hilarious, though, that people are open to this possibility but so hostile to the idea of creationism.

There's "creationism," meaning the belief in an entity that created the universe, and then there's "Creationism," the belief that the creation of the universe is documented in a 2000 year old book, in spite of centuries of diligently gathered evidence of our own inquiring minds the contrary.

" the belief that the creation of the universe is documented in a 2000 year old book,"

Genesis is in the old Testament, so its more like a 3400 year old book.

The "Creationists" in the USA should be called 'Young Universe Creationists' or YUC'sThey think that the universe is only N thousand years old, whereas scientific evidence points to N billion years, and many 'People of Faith' in the rest of the world don't agree with their interpretation.

I find it hilarious, though, that people are open to this possibility but so hostile to the idea of creationism.

If you ask me, it's the same shit in a different package. Throughout most of early history, man had a pretty bad understanding of scientific principles and "God made everything" was an answer that fit what was observable at the time. As advances in scientific understanding were made, we've come up with theories as to why we're here that are have a higher likelyhood of being true based on observations (the Big Bang, for example). It's also just as likely we were observing some advance's alien race's fireworks show that predated our known universe, but just because that fits the observation, does not mean it's true.

For example, if I put you in a completely darkened room and you heard meowing, would you know for absolute certain that there was a cat in the room? It could've been a recording of a cat, a person making a meow noise or even a parrot that was trained to meow. You could've said that "I heard a cat, so there is a cat in the room." and it would've fit your observation, but it could still be entirely incorrect. Likewise, these scientists may believe "the universe is a simulation" fits their observations. Just remember, until you can turn on the lights and see for sure - all that meows may not be a cat.

Great point. I was in a PhD program in Ecology and Evolution, and also have written several computers simulations, and I have known about Fredkin's "the universe is a simulation" ideas since the 1980s. As I said before in some Slashdot posts, if you are serious about scientific skepticism, you have to admit is is possible we live in a simulation that has only been running for 6000 (or whatever) simulated years, and was started either from a check pointed version or started from some hand-crafted parameters and data files. Creators of such hand-crafted environments might perhaps be assisted by guided evolutionary processes like used in our PlantStudio 3D software or EvoJazz musical software, where a user picks from a set of variations over and over again to craft something (and originally inspired by Richard Dawkins "Blind Watchmaker" software). Using such tools may muddy the waters of what a "generation" means though, and it also seems likely organisms evolved together to produce their complex interrelationships in ecological webs.

In any case, the universe might be a simulation. It might even just be a game we stepped into for an afternoon, with artificial memories implanted as in some Star Trek Holodeck scenarios. And we may not know until it is over (if then, if our consciousness persists). And even then, how many levels of nesting and branching are they in a multiverse of universes? Maybe C.S. Lewis was right, when characters feel at the end of the Narnia novels that a better heaven even closer to "God" somehow remains "ever inward, ever upward"? Still, does God have a God? And so on? If so, do they all agree on what morality should be in a consistent way? Or is it just turtles some or all the way up and we need to make a morality that promotes life and community? Or is it just exactly the way some specific version of the Christian Bible say, and the fossil record and geological record is a test of faith?

All that said, on a practical basis we can see evolutionary processes happening all around us (like with the flu virus mutating every year or bacteria become antibiotic resistant over time). As I said above, even if the universe was designed and only running for 6000 simulated years, evolutionary processes may have been be part of tools used to help make it. The fossil record may indeed have been placed there as a test of faith, and yet, would such a god be worthy of worship except out of fear? So, on a practical basis, we have to work with a lot of assumptions about a vast universe in age, extent, and complexity where evolutionary processes are important -- while at the same time honoring the mystery of it all, especially the mystery of consciousness we dwell in every second.

The universe might also have been run for a long time up to a check point (like getting Linux set up nicely in VirtualBox) and then might just be run endlessly from that checkpoint. I'm not sure how "old" that would make this current run of the universe simulation then if the run was started only 6000 simulated years ago, but the check pointed version it was started from was let run for 14 billion simulated years before that?

Anyway, just various interesting speculations on the great mystery which probably is way beyond human-brain-sized comprehending. It is the height of hubris to think we really can understand the universe of universes in

If we are in a simulation, and it's like any of the games we play or simulations we run for science there's some purpose or driver. Since were simulating at the level life and not just some abstract physics, then it's reasonable that some of the beings here are avatars. Who might those be? Well Duh. Celebreties. Or people who seem to achieve huge success with little effort like say Branson or J.P Diamond.

So go be a groupie. If you aren't interacting with a celebrity then your life is wasted. It's yo

Then, humans started coming with very silly ideas about the model actually being the reality it models.

Humans aren't real. They are merely a hodge-podge of organs acting in concert which obey the standard medical model. Organs are simply groups of cells that act in concert, which obey the standard biological model. Cells are made of molecules which obey the standard organic chemical model. Molecules are merely structured atoms obeying the standard chemical model. Atoms are composed of bosons, fermions and hadrons, and hadrons are small clumps of quarks I think, and all these subatomics obey the standard nuclear model (aka the "Standard Model"). Bear in mind, all matter by volume is 99.999%+ empty space, and that none of the models I mentioned are empirically real; they are abstract. We just use them to help explain our observations, and they help the math come out neat. Thus, as humans are comprised of aggregates that are also comprised of more fundamental aggregates, etc., they're mostly just a convenience of language.

Not to mention that he's a bit of an antisocial asshole. He kicked out Adam and Eve after putting the trees there (as an omnipotent being he could've put them anywhere) and then punishing them for using them (as an omniscient being he must have known that this will happen). Not to mention that I'd get into trouble if I tried to flush down a failed experiment.

And I bet he never had any kind of approval from some ethic commission for his human experiments.

If I did a fraction of what he committed on humanity I'd be hunted down and dragged to Den Hague, then locked up with the key being thrown away. But he gets praise and worship.

I know you're trying to be funny but let's consider what the Bible says. First omnipotence. Briefly 1 John 4:8 tells us God is love and James 1:13 tells us he doesn't put the tree there to cause them to fail. As a loving parent expected the obedience of his human children (Rev 4:11).

Now omniscience. Though he has the ability to exercise foreknowledge. He selectively uses it. See the examples at Genesis 11:5-8 and Ge 18:20-22
of occasions where he didn't exercise his foreknowledge but chose to make a deci

Deuteronomy 20:17 [wmflabs.org]: But thou shalt utterly destroy them: the Hittite, and the Amorite, the Canaanite, and the Perizzite, the Hivite, and the Jebusite; as the LORD thy God hath commanded thee;

Deuteronomy 7:1 [wmflabs.org]: When the LORD thy God shall bring thee into the land whither thou goest to possess it, and shall cast out many nations before thee, the Hittite, and the Girgashite, and the Amorite, and the Canaanite, and the Perizzite, and the Hivite, and the

Yeah, there is also that part where we are told that "All mankind are sinners and guilty before God" and from the start Adam and Eve are told that the penalty rebellion against God (sin) was death too. So all you are stating is that God exercised His divine right to pass a holy and just judgement on guilty people instead of extending further grace (not getting what you deserve) to them. So technically God is free to do the exact same thing to us, as everyone on earth stands before God guilty.

First: humans observed the universe.Next, humans invented mathematics to model these observations.Then, humans refined mathematics over time, to even better model these observations.Then, humans became surprised at how well their model fit the universe, seeming to have forgotten how hard they worked to make it so.Then, humans started coming with very silly ideas about the model actually being the reality it models.

The inclination to have faith in something fanciful doesn't always come from the religious.

Even older news:World on a Wire - 1973 ("The Thirteenth floor" - see parent - is a remake of this one)http://www.allmovie.com/movie/world-on-a-wire-v144137http://www.imdb.com/title/tt0070904/?ref_=nm_flmg_wr_29

[Neo sees a black cat walk by them, and then a similar black cat walk by them just like the first one]Neo: Whoa. Déjà vu.[Everyone freezes right in their tracks]Trinity: What did you just say?Neo: Nothing. Just had a little déjà vu.Trinity: What did you see?Cypher: What happened?Neo: A black cat went past us, and then another that looked just like it.Trinity: How much like it? Was it the same cat?Neo: It might have been. I'm not sure.Morpheus: Switch! Apoc!Neo: What is it?Trinity: A d

If we are trapped in a VR, so a tree that fall in a forest when nobody is there to listen wont do any noise because it's it's will be a use of computer power unuseful. Maybe Sartre was right after all.

If we are trapped in a VR, so a tree that fall in a forest when nobody is there to listen wont do any noise because it's it's will be a use of computer power unuseful.

Contrast with "Butterfly effect": how can you know the fall of the tree will not be needed for future events?
If you assume the VR programmer is able to determine it in advance, then what would be the motivation behind the simulation?

To me, it's more likely that the VR tree failing will still produce a VR sound; to determine the evolution of the system, it is more likely the programmer does not have any solution with a "lower cost" than actually running the simulation.

How could math not permeate our universe? There has to be some sort of structure or priors. And once, you have that, you have something that math can work on. And once you have that, you have math permeating your universe.

1. In how many dimensions is this supposed simulator living?2. Is the simulator itself embedded inside another simulator?3. Why then, do we have only 3 spatial dimensions?4. What are the chances of us being at the bottom of an infinite chain of simulators?

The simulation was implemented in a language which was, like most other languages, derived from ALGOL 68. The developers found that if they went beyond three dimensions, the array indexing syntax became too cumbersome to deal with.

Three dimensions is the only number of dimensions that allows objects to easily pass by / through each other but still allow for frequent interaction. In 2D, everything just runs into it's neighbors all the time. In 4d, you'd almost never have a collision, and long range forces would be too weak to do anything interesting.

Even were we to imagine some technology and technology advanced civilization capable of simulating an entire world, the minds within them, and anything that such minds can perceive and be affected by (i.e. we can perceive and be affected by atoms, electrons, quarks, etc but we can not perceive or be affected by an atom or particle say 100 million light years away) - even if we postulate such an enormous computing capacity - the capacity has to be finite. Even were the "computer" running the simulation the

For this to be true in even the most allegorical sense would require that we stretch the definitions of "computer" and "simulation" well beyond anything we currently understand and well beyond the bounds of our ability to be concise and specific about what the terms mean. Using these terms here is just mixing up apples and oranges.

We might as well, in other words, say that our universe is a blender inside a giant appliance store, a stageplay inside a giant theatre district, a mildewing blow tickler inside a giant hoarder's garage mess, or anything else bearing the one of the rough relationships signal:carrier, content:form, fragment:whole, instance:structure, etc.

I mean, what sort of computer are we talking about here?What is its nature, not just logically, but physically? Do we even know that we're speaking "physically"? Isn't this the scale at which such quantities break down?And doesn't our idea of computation and simulation require precisely that mathematical rules apply for these to be carried out in the first place?

We might as well, in other words, say that our universe is a blender inside a giant appliance store, a stageplay inside a giant theatre district, a mildewing blow tickler inside a giant hoarder's garage mess, or anything else bearing the one of the rough relationships signal:carrier, content:form, fragment:whole, instance:structure, etc.

You had me at "blow tickler", because I don't know what it is but it sounds naughty.

if we're conflating matter with information or information-processing.

A blender perfectly simulates what happens in a blender, mapping matter to information. It is empirically perfect, in that every possible unit of information is represented by a dedicated unit of matter, without shortcuts; it is a perfect simulation of what happens in the theoretical case of "something being blended" which is a subset of the logically possible set of phenomena connected to the physical manifestations found in an appliance

If the simulation is completely perfect, then it also must have a near infinite amount of memory as well, or else little inconsistencies would be manifest and detected. But philosophically, if one were to create a simulation, and that simulation is perfect and infinite in size and scope, then it is by definition the same as if you had created the universe. So really it doesn't matter, except to mathematicians whether or not it's a simulation or reality. It's fundamentally equivalent at this scale.

If we are living the simulation, then the program has already been written, so it must have been a programmer of the past. There is nothing 'futuristic' about it, except that the programmer might have a better computer than any of ours.

Maybe we are, and maybe we aren't. Without a way to find out, a way to get out, or a way to influence the outside in a way that's useful to us inside, what is the point of this speculation? It's practically equivalent to the philosophical position that it's all a dream, which is something that every culture seems to come with from time to time, and it's always a totally useless theory. It just doesn't lead anywhere; it's a logical dead end.

a way to get out, or a way to influence the outside in a way that's useful to us inside, what is the point of this speculation?

Really? Speculation got our species where we are today. If scientific discoveries had to wait around until someone in pursuit of a practical goal found them, we'd still be leaving in hovels and crapping out of the window.

While an interesting thought experiment, somehow I think that the conclusion is irrelevant. If we decide to distinguish between reality and a hyper advanced simulation, what is reality, if not just that? Reality or simulation, this is the universe we live in.

I mean, a Designer that watches what you do, and is very interested in your behavior. Has set some rules that you must obey, but won't communicate with you. It's everywhere, can see the past and the future as a single continuum, can change reality, it's omnipotent but has chosen to limit It's own power....

Quantum physics seems to be the ultimate proof that the universe is a simulation.

The universe, intuitively, seems to be analog and continuous. That "feels" right to us. But quantum physics shows that it is actually discrete. But that is exactly how computer simulations work! They use very small time scales to make things appear continuous. We know that below certain time scales, things are essentially random. This is consistent with a computer simulation. You can't accurately simulate something that happens in less time than one "frame" of time. There is a whole area of mathematics that deals with how to make simulations work accurately [wikipedia.org] given the limitation of discrete time scales.

The same happens with physical sizes. Below the Planck scale [wikipedia.org] the universe starts to break-down and become random. This is exactly how things would work if the universe was using binary arithmetic. Suppose that every particle in the universe has a coordinate. You can represent it's position over a vast scale, but only with limited accuracy. The plank scale is that limit, and it indirectly tells us how many bits are in the coordinate field of each particle. When we try to measure the position of something accurately, we find that the position becomes random. And if you try to measure it's speed to more resolution than one "frame" of time, it becomes less accurate. Worse-yet: the only way we can measure the position or speed of a simulated particle is by comparing it to another simulated particule, which introduces yet more error. We are ultimately limited by the accuracy of the simulation.

One side-benefit of this is that we have an awesome source of stastically predictable randomness. Quantum computers are actually using the randomness of the simulator to take advantage of cpu-cycles that are "outside" of our universe. Within the simulator, we can only build a computer that is so fast. But if we find a way to tap into the computing power of the simulator, like by using the side-effects of one of it's built-in functions, then we can compute a result faster than anything we can do ourselves. It is like calling into "native code" while we are running in the interpreted bytecode.

Another indication that we are in a simulation is that quantum physics shows us that wave functions collapse when we observe them. That makes sense: why should the universal simulator waste time calculating quantities that are not currently being measured? Imagine a vast number of inputs, a vast number of calculations that produce outputs, and a smaller number of observers of those outputs. You can easily optimize away things that are not being observed. But we found a way to notice the side-effect of not calculating certain values. It's like a side-channel attack on an encryption algorithm. You can tell how many bits of a password are correct even without the output by seeing how long it took to calculate, or how much power the computer consumed. I wonder if the designers of the simulator didn't know that we could see these kinds of side-effects, or if they are too difficult to fix. Either way, we are seeing side-effects of some of the shortcuts and optimizations.

Perhaps one day one of the programmers will look over at their printer and find a little note from someone way down here inside the simulation. If you could hack a few words outside of the system, what would they be?

Mathematics, especially simulation, is actually a very weak approach to physical phenomena in themselves. It's good for human insight *about* the phenomena, but in most cases the equations are intractable and a simulation is miserably inefficient at getting the specifics right. A small molecule can assemble itself in picoseconds without mathematics, but a simulation takes a huge supercomputer run. If you'd like to simulate something bigger, you'll find that simulation scales very badly.

A couple of thoughts come to mind: one is what the nature of the simulation (if we accept the simulation argument for a moment ) tell us about the nature of the programmers? Certainly we know that, considering the tens of millions killed in our various recent world wars as well as the millions of innocent children who starve to death every year, that the whatever the "programmers" of our universe are, they have no more consideration for us as we would for various cultures of bacteria killed off to test a new antibiotic. I wonder what else we could infer about the "programmers" simply by observing our own world.

Secondly I wonder if it would be somehow possible for the beings inside the simulation to "hack" the simulation itself somewhat how a computer virus in our machines can cause unexpected/unwanted/unplanned for behaviors in our computer systems. What would you have to do to corrupt and possibly take over the program running the simulation of our universe?

Hmm. A Deja vue [slashdot.org]. A glitch in the matrix?
Seriously,such ideas are already a cliche. It had already been subject to fascinating contemplations in Hofstadters book [wikipedia.org] of 1981.
And progress in virtual reality and computer games since then have only amplified that the idea of a simulation would be hard to detect.

Every once in while people claim that the universe works at our current level of technology. Right now we are at the computer and simulation stage. This has been going for years. In fact there are a couple interesting books that posit certain things in our universe, such as the Heisenberg uncertainty principle, on the basis of information theory, i.e. that we can only know limited things about the universe as there are only a limited number of bits that can be stored.
The flaw in all these hypothesis is that although we have modeled the universe for the past 400 years using math, those models have always been a simplification of our observations. The predication we make from them have always been an projection of what we think exists. In most cases we do not observe these predictions directly, so it may be that we create the formulation we expect to see.
This is not to say that science models are not the best we have available. These models allow us to fly to far off planets, build computers, and create complex networks. The practical extent to science cannot be underestimated. But that is actually explains what is happening 'for real'. The is epistemology. It unscientific. It is extrapolating outside of the domain of our knowledge with no real way of testing if the extrapolation is valid.

I am not stressed out by the notion we might live in a simulation because it changes nothing about the fundemental questions about the nature of reality, it only changes the context in which we ask them. It does add a whole new layer of interesting questions to examine, but strip away the stimulation and you are left where you were before.

Maybe, but if we are living in a simulation maybe the real world has characteristics that change the question.

Maybe the real world has deities that are regularly and obviously involved with the running of the reality and our universe is the results of an experiment that says "what happens if there are no visible gods?"

Or maybe they're mostly happily atheistic and they're wondering what would happen if people were given a more superstitious nature.

Maybe they're energy beings wondering what would happen if you change the laws of physics to allow these massive fireballs they called stars to form, and we're some kind of weird phenomena that's popped up in the simulation. Our consciousness isn't really a feature of our universe but a flaw the simulation that they don't notice because in the real world consciousness is a phenomena that occurs everywhere and is easily explainable.

If we are living in a simulation there's really not a lot we can assume about what's going on outside.

>If we are living in a simulation there's really not a lot we can assume about what's going on outside.

I beg to differ. We can probably infer a lot. For instance:

- Considering the amount of injustice, starvation, and people killed in wars we can assume that the programmers are indifferent to us , much as we would be indifferent to the millions of bacteria colonies killed off when we test a new antibiotic.

- We can infer that time runs much slower for the programmers (or perhaps that they are almost unim

The primary problem with this assumption is that it assumes that "time" exists outside of the simulation.

I've written simulations in the past that allowed me to rewind time and try a different possible random outcome. It's not that hard, provided you can store the states, and the things inside the simulation (asynchronous logic gates) could not have detected that it happened. They always saw a legitimate consistent history. It's only from our position outside the simulation that you would know that time had been rewound and a different path taken. What's more, if I'd used a breadth-first search strategy for e

If your life and the events thereof had been run through the simulation more than once, without that knowledge being a designed part of the simulation, how would you know? You are, after all, a part of said simulation.

I've given this idea some thought as well, but the conclusion I've come to is that I don't think that we're part of a computer simulation. I do, however, think that whatever it is that makes the universe possible is liable to operate on principles similar to a computer, and may even be somehow

Even if the universe actually is deterministic, it appears to present us with an illusion of free will, that is, we can analyze a set of data presented before us, and make what we believe is a free willed decision about what to do in the future. This apparent free will is indistinguishable to us from what actual free will may be, and is, in fact, sufficient to suggest that both that free will actually does exist and in turn that the universe is non-deterministic.